#!/usr/bin/python

# Interactively prompts for variable values
# expected arguments are
# command -d [default-xml [custom-xml [ consolidated-xml ]]]
#
# -d is for the myplc-devel package

# we use 3 instances of PLCConfiguration throughout:
# cdef : models the defaults, from plc_default.xml
# cread : merged from plc_default & configs/site.xml
# cwrite : site.xml + pending changes

import sys
import os
import re
import readline
import traceback
from optparse import OptionParser

from geni.util.config import Config

usual_variables = ["GENI_REGISTRY_ROOT_AUTH",
                   "GENI_REGISTRY_LEVEL1_AUTH",
                   "GENI_REGISTRY_ENABLED",
                   "GENI_REGISTRY_HOST", 
                   "GENI_REGISTRY_PORT",
                   "GENI_AGGREGATE_ENABLED",
                   "GENI_AGGREGATE_HOST",
                   "GENI_AGGREGATE_PORT",
                   "GENI_SM_ENABLED",
                   "GENI_SM_HOST",
                   "GENI_SM_PORT",
                   "GENI_PLC_USER",
                   "GENI_PLC_PASSWORD",    
                   "GENI_PLC_HOST",
                   "GENI_PLC_PORT",
                   "GENI_PLC_API_PATH"
                   ]


mainloop_usage= """Available commands:
 u/U\t\t\tEdit usual variables
 w/W\t\t\tWrite / Write & reload
 q\t\t\tQuit (without saving)
 h/?\t\t\tThis help
---
 l/L [<var>]\tShow Locally modified variables/values
 s/S [<var>]\tShow all current variables/values 
 e/E [<var>]\tEdit variables (all, in category, single)
---
""" 

command_usage="%prog [options]"
command_usage += """
  Unless you specify the -d option, meaning you want to configure
  using defaults without interactive prompts""" 

variable_usage= """Edit Commands :
.\tStops prompting, return to mainloop
=\tShows default value
?\tThis help    
"""

def save_config(changes, config_file):
    # always validate before saving
    changes = validate(changes) 
    
    cfile = open(config_file, 'r')
    lines = cfile.readlines()
    newlines = []
    cfile.close()
    for line in lines:
        added = False
        for variable in changes:
            if line.startswith(variable):
                try:
                    value = int(changes[variable])
                    newline = '%s=%s\n' % (variable, value)
                    newlines.append(newline)
                except:
                    value = changes[variable]
                    newline = '%s="%s"\n' % (variable, value)
                    newlines.append(newline)
                added = True
                break
        if not added:
            newlines.append(line) 
    
    cfile = open(config_file, 'w')
    cfile.writelines(newlines)
    cfile.close()

def validate(changes):
    defaults = get_defaults()
    
    if not changes:
        return

    # GENI_INTERFACE_HRN is generated by combining GENI_REGISTRY_ROOT_AUTH and 
    # GENI_REGISTRY_LEVEL1_AUTH, so if either of these are present we must 
    # update GENI_INTERFACE_HRN
    if 'GENI_REGISTRY_ROOT_AUTH' in changes:
        root_auth = changes['GENI_REGISTRY_ROOT_AUTH']
    else:
        root_auth = defaults['GENI_REGISTRY_ROOT_AUTH']
             
    if 'GENI_REGISTRY_LEVEL1_AUTH' in changes:
        level1_auth = changes['GENI_REGISTRY_LEVEL1_AUTH']
    else:
        level1_auth = default['GENI_REGISTRY_LEVEL1_AUTH']
                
    interface_hrn = ".".join([root_auth, level1_auth])
    changes['GENI_INTERFACE_HRN'] = interface_hrn
    return changes                            

def get_defaults():
    geni_config = Config()
    plc_vars = {'PLC_API_MAINTENANCE_PASSWORD': 'GENI_PLC_PASSWORD',
                'PLC_API_MAINTENCE_USER': 'GENI_PLC_PASSWORD'
               }
    try:
        from geni.util.config import plcConfig
        plc_config = plcConfig
    except:
        plc_config = None
    
    defaults = {}
    for var in dir(geni_config):
        if var.startswith('GENI'):
            value = eval("geni_config.%s" % var)
            defaults[var] = value

    # some defaults come from plc_config
    for var in dir(plc_config):
        if var in plc_vars:
            value = eval("plc_config.%s" % var)
            defaults[plc_vars[var]] = value

    return defaults       

def prompt_variable(variable, default_config):
    if variable in default_config:
        default_value = default_config[variable]
    else:
        default_value = ""  
   
    while True:
        prompt = "%(variable)s : [%(default_value)s] " % locals()
        try: 
            answer = raw_input(prompt).strip()
        except EOFError:
            raise Exception ('BailOut')
        except KeyboardInterrupt:
            print "\n"
            raise Excception ('BailOut')

        if (answer == "") or (answer == default_value):
            return default_value
        elif answer in ['""', "''"]:
            return ""
        elif (answer == "."):
            raise Exception ('BailOut')
        elif (answer == "?"):
            print variable_usage.strip()
        elif (answer == "="):
            print ("%s defaults to %s" %(variable,default_value))
        else:
            return answer

def show_variable(variable, value_dict):
    print "%s=%s" % (variable, value_dict[variable])                    
    
def mainloop (default_config, config_file):
    changes = {}
    while True:
        try:
            answer = raw_input("Enter command (u for usual changes, w to save, ? for help) ").strip()
        except EOFError:
            answer =""
        except KeyboardInterrupt:
            print "\nBye"
            sys.exit()

        if (answer == "") or (answer in "?hH"):
            print mainloop_usage
            continue
        if answer in ['?']:
            print "help"  

        if (answer in ["q","Q"]):
            return
        elif (answer == "w"):
            save_config(changes, config_file)
        elif (answer == "u"):
            try: 
                for varname in usual_variables:
                    changes[varname] = prompt_variable(varname, default_config)
            except Exception, inst:
                if (str(inst) != 'BailOut'):
                    raise
        elif (answer in ["e","E"]):
            try:
                prompt_variable (cdef,cread,cwrite,category,variable,
                                 show_comments,False)
            except Exception, inst:
                if (str(inst) != 'BailOut'):
                    raise
        elif (answer in "sS"):
            for varname in usual_variables:
                show_variable (varname, default_config)
        elif (answer in "lL"):
            if not changes:
                print "No changes to display"
            else:
                for varname in changes:
                    show_variable(varname, changes)
        else:
            print ("Unknown command >%s< -- use h for help" % answer)

####################
def main ():

    command=sys.argv[0]
    argv = sys.argv[1:]
    save = True
    parser = OptionParser(usage=command_usage, version="%prog 1.0")
    parser.set_defaults(config_dir="/etc/geni",
                        usual_variables=[])
    parser.add_option("","--configdir",dest="config_dir",action="append", help="specify configuration directory")
    parser.add_option("","--usual_variable",dest="usual_variables",action="append", help="add a usual variable")
    parser.add_option("-d", "--default", action="count", help="dont prompt for values, just use defaults")
    (config,args) = parser.parse_args()
    if len(args)>3:
        parser.error("too many arguments")

    config_dir = parser.values.config_dir
    config_file = os.sep.join([config_dir, 'geni_config'])
    defaults = get_defaults()
    # if -d is specified dont prompt, just configure with defaults
    if '-d' in argv:
        save_config(defaults, config_file)
    else:        
        mainloop (defaults, config_file)
    return 0

if __name__ == '__main__':
    main()